632
FXUS61 KPHI 312137
AFDPHI
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MOUNT HOLLY NJ
537 PM EDT MON AUG 31 2026
WHAT HAS CHANGED
UPDATED RIP CURRENT SECTION.
KEY MESSAGES
1. ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE THROUGH THE DAY
AND INTO TONIGHT, BUT THE RISK OF HAZARDOUS WEATHER IS LOW.
2. HEAT AND HUMIDITY WILL BUILD INTO THE MIDDLE OF THE WEEK,
ALONG WITH DAILY CHANCES FOR SHOWERS AND THUNDERSTORMS. THERE IS
AN INCREASING THREAT OF SEVERE THUNDERSTORMS AND POTENTIALLY
FLASH FLOODING DURING THE MIDDLE OF THE WEEK, NAMELY TUESDAY
THROUGH THURSDAY.
DISCUSSION
KEY MESSAGE 1...ISOLATED SHOWERS AND THUNDERSTORMS POSSIBLE
THROUGH THE DAY AND INTO TONIGHT, BUT THE RISK OF HAZARDOUS
WEATHER IS LOW.
RISING HEIGHTS AND JET DYNAMICS ALOFT EARLY IN THE DAY SHOULD
WORK TO SUPPRESS CONVECTION UNTIL THE AFTERNOON OR EVENING,
WHEN CONDITIONS WILL BECOME MORE FAVORABLE FOR SOME ISOLATED
SHOWERS AND STORMS TO DEVELOP. INSTABILITY WILL BE LOW (LESS
THAN 1,000 J/KG) AND LAPSE RATES WILL BE POOR, BUT PWATS ARE
FAIRLY HIGH (OVER 1.5"). SO NOT EXPECTING ANY SIGNIFICANT OR
HAZARDOUS WEATHER OUT OF ANY CONVECTION TODAY INTO TONIGHT,
HOWEVER CANNOT TOTALLY RULE OUT SOME BRIEF HEAVY DOWNPOURS OR
LOCALLY HEAVY RAINFALL TOTALING AROUND 1-2". THE GREATER
COVERAGE OF CONVECTION INTO THE EVENING SHOULD BE FOCUSED NORTH
OF PHILADELPHIA, WHERE POPS ARE GREATEST. ANY CONVECTION
PERSISTING INTO THE OVERNIGHT PERIOD SHOULD WANE TOWARD DAWN.
HIGHS TODAY WILL BE SIMILAR TO SUNDAY, RANGING FROM THE UPPER
70S TO MID 80S IN MOST AREAS WITH SIMILAR HUMIDITY LEVELS. SKIES
WILL BE MOSTLY CLOUDY, BUT A LUCKY FEW COULD SEE SOME MORE
PERSISTENT SUN. HUMID AGAIN TONIGHT WITH LOWS IN THE MID 60S TO
LOW 70S.
KEY MESSAGE 2...HEAT AND HUMIDITY WILL BUILD INTO THE MIDDLE OF
THE WEEK, ALONG WITH DAILY CHANCES FOR SHOWERS AND
THUNDERSTORMS. THERE IS AN INCREASING THREAT OF SEVERE
THUNDERSTORMS AND POTENTIALLY FLASH FLOODING DURING THE MIDDLE
OF THE WEEK, NAMELY TUESDAY THROUGH THURSDAY.
BROAD UPPER LEVEL RIDGING RETURNS TO THE EASTERN US EARLY THIS
WEEK, BRINGING IN SURFACE HIGH PRESSURE ACROSS THE EASTERN US.
AFTERNOON HIGHS WILL CREEP BACK INTO THE MID 80S TO LOW 90S FOR
MOST AREAS, ABOUT 5 DEGREES ABOVE AVERAGE FOR EARLY SEPTEMBER.
DEWPOINTS WILL ALSO REMAIN IN THE UPPER 60S TO LOW 70S. THE
HOTTEST DAY(S) LOOKS TO BE TUESDAY AND/OR THURSDAY, WHEN HIGH
TEMPERATURES COULD GET INTO THE MID 90S ACROSS DELMARVA AND INTO
THE PHILLY METRO. RESULTING HEAT INDICES WILL BE WELL INTO THE
90S TO AROUND 100 DEGREES. WE WILL CONTINUE TO KEEP AN EYE ON
THE POTENTIAL FOR ANY HEAT ADVISORIES.
ONE OTHER ASPECT TO WATCH WITH THIS RIDGING PATTERN IS THE
POTENTIAL FOR THUNDERSTORMS TO ROTATE AROUND THE PERIPHERY OF
THE RIDGE AND THE POSITION OF A FRONTAL BOUNDARY DURING THE
MIDDLE OF THE WEEK. GUIDANCE MAINTAINS A CONSENSUS THAT THE
PATTERN WILL BE SUPPORTIVE OF MULTIPLE ROUNDS OF THUNDERSTORMS,
ESPECIALLY DURING THE TUESDAY THROUGH THURSDAY TIME FRAME.
SPC MAINTAINS A SLIGHT RISK (2 OF 5) FOR SEVERE THUNDERSTORMS
TUESDAY FOR PORTIONS OF THE AREA, AND A SLIGHT RISK HAS BEEN
INTRODUCED FOR WEDNESDAY. IT SHOULD BE NOTED THAT THERE HAVE
BEEN SOME INDICATIONS IN THE GUIDANCE THAT WEDNESDAY'S SEVERE
POTENTIAL WILL BE MUCH MORE CONDITIONAL, AS A FRONTAL BOUNDARY
LOOKS TO BE DRAPED ACROSS OUR AREA WITH POTENTIAL FOR EASTERLY
WINDS AND MARINE INFLUENCE AT THE SURFACE. THIS DOESN'T MEAN
THERE WOULD BE ZERO SEVERE POTENTIAL, BUT ADDS A FURTHER DEGREE
OF UNCERTAINTY TO WEDNESDAY'S SETUP. THURSDAY REMAINS
HIGHLIGHTED WITH 15% PROBABILITIES FOR SEVERE THUNDERSTORMS. THE
NORTHWEST FLOW PATTERN THAT WILL BE IN PLACE WILL BE SUPPORTIVE
OF ALL SEVERE THREATS, INCLUDING DAMAGING WINDS, LARGE HAIL,
AND TORNADOES. THE THREAT FOR FLASH FLOODING IS TYPICALLY LOWER
WITH THESE PATTERNS, HOWEVER GIVEN MULTIPLE DAYS WITH THE
POTENTIAL FOR STORMS AND RECENT HEAVY RAINFALLS, AT LEAST SOME
RISK FOR FLASH FLOODING WILL EXIST.
LONG STORY SHORT, THE TUESDAY THROUGH THURSDAY PERIOD LOOKS
VERY ACTIVE WITH MULTIPLE ROUNDS OF THUNDERSTORMS ACROSS THE
REGION, BUT DETAILS STILL REMAIN UNCLEAR. STAY TUNED FOR
UPDATES ON THESE THREATS OVER THE COMING DAYS.
BY FRIDAY, CURRENT MODEL CONSENSUS INDICATES THE FRONTAL
BOUNDARY WILL BE PUSHING INTO AND SOUTH OF OUR REGION WITH
CANADIAN HIGH PRESSURE BUILDING ACROSS THE NORTHEAST. THIS
SHOULD FAVOR AN END TO SEVERE WEATHER AND FLASH FLOODING
POTENTIAL. LABOR DAY WEEKEND IS STILL SHAPING UP TO FEATURE NICE
WEATHER, WITH TEMPERATURES TRENDING SLIGHTLY BELOW NORMAL AND
LOWER HUMIDITY.
AVIATION /21Z MONDAY THROUGH SATURDAY/
THE FOLLOWING DISCUSSION IS FOR KPHL, KPNE, KTTN, KABE, KRDG,
KILG, KMIV, KACY AND SURROUNDING AREAS.
TODAY...PREVAILING VFR CONDITIONS EXPECTED. LIGHT RAIN SHOWERS
TRACK ACROSS THE WESTERN PORTIONS OF THE FORECAST AREA,
ALTHOUGH NO RESTRICTIONS ARE EXPECTED. ONLY IMPACT WILL BE OVC
OR BKN CEILINGS THROUGHOUT THE DAY. NORTHEAST WINDS IN THE
MORNING AROUND 5 KTS, SHIFTING TO A MORE SOUTH TO SOUTHEASTERLY
DIRECTION BY 18Z AROUND 5 KTS OR LESS. WINDS MAY BECOME LIGHT
AND VARIABLE AT TIMES. THERE IS A LOW (GENERALLY LESS THAN 20%)
CHANCE FOR ISOLATED SHOWERS OR STORMS WHICH COULD CAUSE BRIEF
RESTRICTIONS IN THE AFTERNOON. MODERATE CONFIDENCE.
TONIGHT...MVFR CEILINGS LIKELY DEVELOPING BY 06Z. SCATTERED
SHOWERS AND PERHAPS A FEW STORMS AROUND AT TIMES, ESPECIALLY
BETWEEN 00Z-06Z. REDUCTIONS IN VISIBILITIES ARE UNLIKELY
OUTSIDE OF ANY BRIEF RAIN SHOWERS OR STORMS. WILL CONTINUE TO
INCLUDE PROB30 GROUPS FOR TAF SITES THAT HAVE A MEANINGFUL
PROBABILITY OF TSRA EARLY IN THE NIGHT. WINDS SETTLING OUT OF
THE SOUTH TO SOUTHWEST AROUND 5 KTS OR LESS. MODERATE
CONFIDENCE. AFTER PRECIPITATION MOVES OUT OF THE TAF SITES, HAVE
INTRODUCED IFR CEILINGS TO PHL, ABE, TTN, AND PNE. CEILINGS
IMPROVE TO MVFR AND THEN VFR THROUGHOUT TUESDAY MORNING.
OUTLOOK...
TUESDAY THROUGH THURSDAY...RESTRICTIONS POSSIBLE IN SHOWERS AND
THUNDERSTORMS EACH DAY, MAINLY DURING THE AFTERNOON TO EVENING
HOURS.
FRIDAY...PRIMARILY VFR.
MARINE
NO PREVAILING MARINE HAZARDS EXPECTED. EAST TO SOUTHEAST WINDS
AROUND 5-10 KTS. SEAS 1-2 FEET. GENERALLY FAIR WEATHER ASIDE
FROM AN ISOLATED SHOWER POSSIBLE.
OUTLOOK...
TUESDAY THROUGH FRIDAY...NO PREVAILING MARINE HAZARDS EXPECTED.
CHANCES FOR THUNDERSTORMS EACH DAY, MAINLY IN THE AFTERNOON AND
EVENING HOURS.
RIP CURRENTS...
FOR TUESDAY, SOUTH-SOUTHWEST WINDS WILL AVERAGE AROUND 10 MPH.
BREAKING WAVE HEIGHTS AROUND 1 TO 2 FEET WITH A 1 TO 2 FOOT
SOUTHEAST SWELL AROUND 7 TO 8 SECONDS. GIVEN THESE CONDITIONS,
HAVE OPTED TO CONTINUE WITH A LOW RISK FOR THE DEVELOPMENT OF
DANGEROUS RIP CURRENTS FOR BOTH THE JERSEY SHORE AND DELAWARE
BEACHES.
FOR WEDNESDAY, EAST-NORTHEAST WINDS WILL AVERAGE AROUND 10 TO 15
MPH. BREAKING WAVE HEIGHTS WILL VARY BETWEEN 2 TO 4 FEET FOR
NORTHERN BEACHES, WITH 1 TO 3 FEET FOR SOUTHERN BEACHES. A
SOUTH-SOUTHEAST SWELL IS EXPECTED WITH MULTIPLE PERIODS. GIVEN
THE STRENGTHENING ONSHORE FLOW AND HIGHER BREAKING WAVE HEIGHTS,
HAVE OPTED TO GO WITH A MODERATE RISK FOR DANGEROUS RIP CURRENTS
FOR MONMOUTH, OCEAN AND ATLANTIC COUNTY BEACHES IN NEW JERSEY;
WHILE OPTING FOR A LOW RISK FOR DANGEROUS RIP CURRENTS FOR CAPE
MAY COUNTY IN NEW JERSEY AND DELAWARE BEACHES.
FOR SPECIFIC BEACH FORECASTS, VISIT WEATHER.GOV/BEACH/PHI
PHI WATCHES/WARNINGS/ADVISORIES
PA...NONE.
NJ...NONE.
DE...NONE.
MD...NONE.
MARINE...NONE.
DISCUSSION...AS/WFO PHI
AVIATION...AS/WFO PHI/STUCK LWX
MARINE...JD/AS/WFO PHI
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